In electronic pre-press systems, images to be printed by offset printing are scanned from photographic sources and digitized. The digitized images are transmitted to a raster image processor (RIP) for half-tone screening and image rasterization. The rasterized image is then transmitted to an imagesetter for photographic recording. Such recording is referred to as imaging or imagesetting, and may for example be performed by photographic recording of an image onto a photosensitive medium such as paper, film or a printing plate. A medium which has had an image recorded onto it by an imagesetter is referred to as "imaged medium".
Existing pre-press systems typically include independent functional units such as an imagesetter for photographically recording images onto media, and a wet chemical processor for developing, fixing and washing the exposed media. A typical photographic imagesetter operates to record a predefined image onto a medium, for example by first mounting the medium onto the internal surface of a drum (i.e. in an internal drum imagesetter), then exposing the medium with a laser beam via a rotatable, optically reflective element mounted along the longitudinal axis of the drum. The medium typically may be supplied as a web or as a cut sheet.
Subsequent to imaging, the imaged medium is passed to a wet chemical processor, where the medium will undergo chemical processing for photographically developing, fixing and washing. If the media was supplied by a continuous web, each sheet of exposed media is cut prior to entry into the processor.
The active chemicals within the fluids in the processor are used to develop, fix and wash the exposed media. These chemicals gradually become inactive, depleted or ineffective over time. At some point, these fluids need to be replenished to be effective, i.e., they drop below a level of effectiveness. Hence, it is desirable to provide a system and method for periodically testing these chemicals. Furthermore it is desirable to implement a system for testing these chemicals which is implemented with minimal effort on the part of an operator, and which will otherwise minimally disrupt the normal operation of the imagesetting system.